Timing tensioner

[maadams]

I have 400ex that has been stroked and bored to a 440 by trinity I Believe. I dont know but think it has stock width timing chain not a 450 chain. Motor keeps breaking timing chain tensioner. It is my friends Quad and I have not seen or done work on this motor. I am sure Motor has aftermarket Cam and springs. The chain guides were in good shape. Anyone have problems like this or ideas.

[UglyMotha™]

I use to have the same problem with mine went thru like two a year, i am now running a adjustable timming chain tensioner from a hayabusa, bolts right in